<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
       *{
           margin: 0;padding: 0;
       }
       header,footer{
           height: 50px; background-color: blueviolet;
           text-align: center; color: cornsilk;
           line-height: 50px;
       }
       main{
           overflow: auto;
       }
       nav,section,aside{
           float: left;
       }
       main>nav{
           width:25%
       }
       main>section{
           width: 50%;
           padding: 0 10px;
           box-sizing: border-box;
       }
       main>aside{
           width: 25%;
       }
       p{
           height:30px ;background-color: crimson;
           text-align: center;margin: 10px 0;
           color: cyan;
       }
    </style>
</head>
<body>
    <header>
        header
    </header>
    <main>
        <nav>
            nav
            <p>lll</p>
            <p></p>
            nav
            <p></p>
            <p></p>
            nav
            <p></p>
            <p></p>
        </nav>
        <section>
            <article>
                article
                <p></p>
                <p></p>
                article
                <p></p>
                <p></p>
                article
                <p></p>
                <p></p>
                article
                <p></p>
                <p></p>
                article
                <p></p>
                <p></p>
                article
                <p></p>
                <p></p>
            </article>
        </section>
        <aside>
            aside
            <p></p>
            <p></p>
            aside
            <p></p>
            <p></p>
            aside
            <p></p>
            <p></p>
        </aside>
    </main>
    <footer>
        footer
    </footer>
</body>
</html>